1. Field of Invention
The present invention relates to a reusable bottle cap for obtaining airtight sealing engagement with a bottle. More particularly, the invention relates to a bottle cap which is highly reliable, easy to operate, and specifically designed for repeatable sealing engagement with various sparkling wine or champagne bottles, each having an annular external lip on the neck of the bottle.
2. Background of the Invention
Various reusable bottle caps have been devised and are commercially available. The least expensive of such caps may adequately seal liquid within a bottle, but over an extended period of time are not capable of retaining effervescence within a sparkling wine, champagne, or similar beverage. A preferred useable bottle cap is easy to operate, relatively inexpensive and, most importantly, is capable of sealing both a liquid and a gas within the bottle, such that a partially consumed beverage stored within its original bottle does not lose its taste.
Some reusable bottle caps are designed such that the sealing member fits within and seals against the generally cylindrical opening in the neck of the bottle. U.S. Pat. No. 3,317,017 discloses a bottle stopper with a generally cylindrical elastomeric seal which expands radially outward into sealing engagement with the internal walls of the bottle neck as the user lifts a knob to raise a piston upward with respect to the seal. Other types of reusable bottle caps employ a threaded mechanism or a lever to expand a seal radially outward into engagement with the interior cylindrical surface of the bottle neck. These devices generally do not possess the ability to retain a slightly pressurized gas within a bottle, and their sealing effectiveness is inherently dependent upon the diameter and surface finish of the interior surface of the bottle neck, which frequently varies with different bottle manufacturers.
Many bottles designed to contain a liquid with a gas over an extended period of time employ a ring-shaped exterior lip around the neck of the bottle. This lip is typically provided, for example, on bottles containing a sparkling wine or champagne. Those skilled in the art of bottle caps have recognized that this annular lip provides a convenient stop for enabling a bottle cap to engage the ring and allow an axially directed downward sealing force to be applied to seal a member with the upper annular surface of the bottle which defines the bottle opening.
U.S. Pat. No. 2,649,220 discloses a container closure having a lower skirt for engaging a radially outwardly protruding bead at the top of the bottle. When positioned on the bottle, a handle can be rotated to force a projection to drive a sealing disk into engagement with the top of the bottle. This device is relatively simple, but practically is designed for only one type of bottle. The device thus has limited utility, and does not suggest modifications which would enable the closure to be used with various bottles having varying axial dimensions between the top of the bottle and an annular projection on the neck of the bottle. U.S. Pat. No. 3,185,332 discloses a bottle cap with a tongue to fit under the bead on the bottle. A roller is provided for fitting under the bead on a radially opposite side of the bottle, and a locking handle retains the roller in place. This bottle cap again offers simplicity, but does not appear to be able to provide the desired sealing force to retain gases in various bottles over an extended period of time.
U.S. Pat. No. 4,770,307 discloses a bottle cap designed to operate in conjunction with an annular indented edge of the bottle below the bead. The device employs a sleeve arrangement to grip the bottle, and a spring to bias a washer into engagement with the top surface of the bottle. No mechanical advantage is available to activate the biasing spring which applies the sealing force. Accordingly, the user may lack the strength to depress the sleeve and overcome the biasing force of the spring to properly apply the cap. If the spring biasing force is minimized to facilitate application by the user, the biasing force may not be sufficient to seal gas within the bottle. Also, user cannot easily detect if the device is sealed to a bottle, since the device when merely placed over the bottle visually appears similar to the arrangement when the device is activated and sealed to the bottle.
Another prior art device employs a seal carried on the lower end of a threaded shaft which is mounted to a base member having a flange for underlying the drip ring of the bottle. The flange anchors the device with respect to the bottle so that the shaft may be threaded downward to bring the sealing member into engagement with the top surface of the bottle. Sealing effectiveness of this device depends upon the force which the user applies to the threaded shaft, and the shaft may undesirably unthread after the cap has been applied to the bottle. The user cannot easily detect if the device is merely positioned on the bottle, or whether the shaft has been torqued to bring the seal into engagement with the bottle. Another device utilizes a pair of pivoting arms to move inwardly and downwardly to engage the drip ring on the bottle. A sealing member is spring loaded to force the seal into engagement with the uppermost surface of the bottle. This device has the disadvantages of the device described in the '307 patent in that no mechanical advantage is available to increase the sealing effectiveness on the bottle. The user may thus not be able to apply the cap to some bottles, while the cap can be easily applied to other bottles but does not provide the desired axially directed force to obtain an effective seal.
The disadvantages of the prior art are overcome by the present invention, and an improved bottle cap is hereinafter described suitable for repeatedly sealing a bottle containing liquid in an airtight manner. Due to the high reliability yet simplicity of the device, the bottle cap of the present invention is particularly well suited for providing an airtight seal with a bottle containing a sparkling wine, champagne, or another effervescent liquid.